Fluid heating element



w.r'. KEENAN, Jh

FLUID HEATING ELEMENT Aug.l 25, 1931.`

` Filed March 23, 1927 NvENToR 30 ditionso use.

. out of suitably thick walled seamless tube vblanks bywelding and forgingjoperations ofl 'Patented Aug. .25,1931

l IUNKIYV'IFED i 1r. immun, Jn., or rELmm, Naw Yonx, Assrenon "r6 roam wmnlm companion, or Naw Yonx, N. Y., .a conrona'rron or-msw Yonx;

` .FLUID :mamme ELEMENT v l application mannen 2s, 1927. sensi No. 177,796.

'y The general object of the present invention is to rovide an improved iiuid heating element adapted vfor use int'supe'rheating steam,

' and in heating'oil, vor fcr other uses, by the 5 absorption of radiant heat 'froma highly heatedvcombustin chamber or other relatively. high temperature; source of radiant heat.A Such elements must have relatively massivewalls, not only to insurethe maintenance of proper strength to resist bursting 4stresses during a suitably prolonged effectiveelement life notwithstanding the tendency to surface deterioration under the condltions of use, but also because the heatconductingproperties of massive walls are essential to a de sirable rate and kind of heat transfer to the fluid being heated.` Heretofore `massive .walled radiant-'heat absorbing elements have been made by shrinking massive .blocks of cast iron onto inner wrought steel tubing, and by forming the elements of cast steel. With elements formed byshrinking blocksl onto. thin walled steel tubes diiiicultles have been experienced because of the resistance to heat iiow across the joints between the inner :tubes and the cast iron blocks, even when those joints'are tight, and also .because the 7 joints between the tubes and' casing blocks frequentl becomeloose under the severe con- The use of cast steel elements is open to the objection that the. cost' of production is unduly high, particularly as-it is not feasible to cast one-piece elements as long as are required by practical considerations y and it is diiiicult and expensive tosatisfactor- .ily unite the ends of thecast steel sections of the element formed of a plurality of such section. Furthermore, it is practically diicult 4o or impossible to form cast steel elements with flow-passages therethrough sufficiently friction loss or pressure'drop inthe elements.

feasible and desirable to formA such elements the character hereinafter set .forth,and my invention consistsfnot only in the-elements described I have discovered .that it is., practically, o the element, that 1s, at the side opposite Aend connections channel ain the element A through the cpenconstructedv as herein described and illus-,

trated, but also in the method employed in the construction ofsuch elements.

The various features of vnovelty' which characterize my invention are pointed out with ,particularityf inthe claims annexed to and forming a part of this specification. l'For a better understanding of the invention, how-.L ever, its-advantages and specific objects a`ttained with its use, reference should be had to the accompanyingv drawings and descriptivematter` in which I have illustrated and preferred embodiments of my ini vention... v i

Of the drawings: l l Fig. 1 is an elevationof an element constructed -in accordance with the present invention; i Fig. 2 is a section on the line 2-2 of Fig-1;V

Fig. 3 is a section on the line 3--3 of Fivl; 1g.

Fig. 3A is a section takensimilarly to ':10

3 of an elementl of different cross section;

Fig. 4 is a partial longitudinalv section.

` taken on the line 4--4' of Fi .2; Figs. 5' to 10 are viewsv lagrammatically illustrating `steps in the` method. of forming the element shown in Fig. 1 out of a cylindrical seamless thick walled tube; and

Fig. 11 is an elevation of modified form. v

The cross section of the body ortion of the finished element A shown in Eggs/1, 2, 3l

an element of i and 4, is rectangularl in form, except that it i V the heat absorbin face of the element. The

communicate 'with the 1 in A in which'the end connections B are or inarily'expanded-to 'se'curethelnv in place and insure tight joints." To -stren hen ,the-- Joints between .the end 4connections and the 10 element' A, the rear Walls of the end portions A of the latter are thickened ordinarily and as illustrated b welding pad or ring-like parts C to the element. The welding operation is preferably carried out by means of an acetylene torch and results in the formation of a fillet of the welding metal D integrally connected to the element and pad C at the,

outer edge of each welded oint.

When formed as hereinafter described, each end wall of the portion of the element formed by the tubular blank contains a saucer-like `regular.

g porting brackets E are welded to the rear side of the element, in the same general manner in which the pad or washer parts C are welded in lace.

In a prel erred mode of forming an element in accordance with the present invention I start with a seamless tube blank a usually of mild steel, and having a wall thickness and a length approximating that of the finished element. Such a tube may be twenty feet ,long with an external diameter of four and one-half inches and a wall thickness of threequarters ofan inch. It will be understood,

, of course, that the foregoing dimensions are given by way of illustrative example, and thatthe invention is not limited to such tube blank dimensions. The tube blank a is first heated to bring one end approximately to a welding temperature, and the heated end is then expanded into the form shown in Fig. 5. In ractice this end expansion may be e fected liy what is essentially a spinning operation, carried out by means of a rotating conical tool F forced vinto the end of the blank a while the tool is being rotated at a suitable speed. VIn practice the tool F may well be coaxial with and removably carried by the rotatable head G'of a machine of the type well known as'a Van Stone machine. After an end ortion of the element has thus been enlarge the end of the enlarged end portion is more or less completely closed by the opera- `tion of suitable spinning tools which may comprise a air o tapered rolls FA shown in Fig. 6, an a second pair f rolls FB shown .in Fig.'7 and operatin on t' e tube end after the rolls FA have per ormed 'their function, the rolls FB being larger 'in diameter and more tapered thany the rolls FA. The rolls FAand FB may well be successively mounted ample, as shown in Fig. tion A of the element direction transverse to the heat absorbing on al@ spindles G of the head G of the vany Stone machine. The end wall of the enlarged element end is then flattened as by'y pressing it against rolls FC journalled in bearings FC removably mounted on the spindles G of the head G. v

After the tube blank end is thus expanded and more or less closed, the enlargedend isl y Off-set with respect to the body of the blank, and it and the portion of the blank body adjacentI the expanded end are given their ,rectangular form. In thus shaping up the expanded end I advantageously first square the'expanded end'with a power hammer provided with work engaging parts H as shown in Fig. 9. If this unduly bulges the closed end as indicated in Fig. 9, the end liattening operation of Fig. 8 may then be repeated. To off-set the expanded end and to give the rectangular form to the body of the blank, I subject the latter to the action of a hydraulic or analogous forging press having,

suitably shaped work holding and work forging parts,v which need not be illustrated or described in detail as those skilled in t-he art will readily understand howto provide and use such parts. v e

After one end and a ortion of the body of the blank have been subjected to the opera-A tions described above, the other end of the blank is expanded, has its end closed, andit and the remaining portion of the blank are shaped by repeating the operations previously described.

After the blank is thus forged into shape, the .cavities A3 and the opening A4 are' filled with welding material, and the pad or washer parts C and the supporting parts E are welded to the blank in the manner previously described. After the completion or in the course ofthe operations, the blank is sub- ]ec'ted tothe straightening operation above described when necessary, and the blank is heated and reheatedas conditions make desirable (at intervals as .the various forging operations are being carried out. Ordinarily the openings A in the blank body and in the washer parts C of the element are reamed out to receive thev tube connections B to be expanded in place-therein after the forging, shaping and welding operations are completed.

Instead of reducing the entire body of the blank to rectangular cross section as shown in Fig. 1, one or more intermediate portions of the blank body may be less fiattened than the remainder of the blank body. For ex- 11, a central ,por- AA is larger in the face of the element than the major portion ofthe element body. This gives increased cross-sectional area to -the element channel in the portion A which may be desirable as iso .v blank'diameter is four an for the application of asoot blowingattachment of certain type.

n forming elements inthe mannerl described, the forging operations by which the' body portion of each element lis given vits rectangular cross section are preferabl carried out so as to -minimize the elongation of the blank bl such operation and in practice, the long si e of the rectangle as seen 1n Fig. 3, isbut little less than the original diameter 4of the blank a. For exam le, if the initial one-half inches the long side of the rectangle as seen in Fig.

l 3 may well befour and three-ei hths inches,

' and with the dimensions herein forevgiven by way of exam le, the elongation of the f body of the blan produced'in the forging operations by which it` is givenv its l`rectangular shape is ordinarily about one-quarter inch per lineal foot of length.

A practical advantage of the invention is that elements having v very different flow capacities can be produced ,from the same standard blank with no changein the operations described above except 1n theextent to "which the blank'is ilattened. For example,

the element AB shown in Fig. 3A maybe f made from a blank identical in cross section with that from which the element A shown in Fig.,3 is made, and by followintg exactly the same steps except-*that the bo y of the -blank is flattened more in forging the body changes in shape are of no'particular consequence. Numerous vvflow passage cross sectional areas intermediate those of the eley ments A and AB may be, and in practice are v l Huid. heating produced from blanks .of the same initial cross section. vThis capacity to produce elementsA of deinitel l different flow capacities from similar blan s and with practically no 'change in the operations require/d except in the extent of the `flattening to vwhich the bodies of the elements are subjected, constitutes an important practical advantage of the invention,.and has the ultimate practical result of facilitating, and cheapening the cost of production of radiant heat absorbing elements suitable for different conditions of The novel method of making a thick walled element disclosed, Vbut not claimed' herein, is disclosed and claimedin v my divisional application, Serial'No. 285,625,

.transverse end connections and having intefiled -June 1.5, 1l28 which hassince maturedy as' Patent No. 1,764,174, granted June 17,' 1930. 'W'" While in accordance'with the rovisions ofthe statutes I have illustrate and described the best form yof my invention'now knownltome, it will be, apparent tothose" skilled in the art that ch n es in the formy of the constructions and m es of o eration herein described and illustrated may e made vention as set yforth in the appended claims, and that certain features of my invention may s'ometimesbe used'with advantage with--l out a corresponding'use` of otherv features.

Having nowdescribed my invention,l what I claim as new and desire to secure by Letters Patent is:

f- 1. Anew article of manufacture consisting of a tubular fluid heating element made of wrought metal and having its end portions internal y and externall enlarged'to provide suitable spaces for tlyie introduction and discharge of the Huid heated from and into gral portions closing the outer end ofv said spaces and having end connectiony openings.

in said enlarged portions and having parts 1- welded to said lend ortions to thicken the portions of the wall t ereof surrounding said openings. y v

.42. A new article of manufacture consisting of a fluid heating element madc'o'ut of a thick walled wrought metal tube blank by forging, lshaping I and weldin operations givm said element a rectangu ar cross sec-l tion, mternally and externally'enlarged end portions and integral'end closing walls.

3.- A new article of manufacture consisting of althick walled tubular fluid heating element integrally formedof wrought metal4 and having an extensive wall portion 'fiattened at its outer side to provide a heat absorbing surface adapted for exposure to a high temperature' source ofradiant heat.

4. A new article of manufacture consistf ing of'a lthick walled tubular Huid. heating element integrally formed of wrought metal and substantially rectangular in transverse` cross section.

5. A new article of manufacture consisting of a one-piece thick walled tubular uid heating element integrally formed of wrought metal and internally and externally i enlarged at its ends.

6. A new article of manufacture consisting of a thick walled ytubular Huid heaLin element integrally formed of wrought met and having its end portions internally and externally enlarged, conduits connected to the rear side of the spaces so formed for the introduction and discharge of the fluid. being heated and integralend portions closing the outer ends of said spaces. 7. article of manufacture consisting of l 75 without departing from the spirit of my 1nn a one-piece thick walled tubular fluid heat element integrally formed of Wrought metal and having' an extensive wall portion atl. tened at its outer side to provide a. heat ab- 5 soi-hing surface adapted for exposure to a. ,v high temperature source o radiant heat, and

conduit, connections to the end portions of said element for Jche introduction and dis.- charge of the fluid to he heated.

m Signed at New York city, in the county of New York, and State of New York, this 19th day of March, A. D. i927,

' WALTER E, HERNAN JR. 4 

